In presently known undercarpet wiring systems, flat multiconductor cables to be connected are arranged either in respective longitudinal abutting relation for splices or in respective orthogonal abutting relation for taps. In the case of the splice, individual conductors are mutually aligned, whereby confusion as to conductors to be interconnected does not arise. An insulation displacing/piercing connector is simply positioned beneath the cable in alignment with each pair of conductors to be connected and is crimped therethrough. One conductor of one cable thus cannot readily be erroneously connected to plural conductors of the other cable.
In the case of tap connections, on the other hand, the possibility of installer confusion and error is quite real. Here, by reason of mutual orthogonality, each conductor of one cable runs in the direction of and may be connected to, all conductors of the other cable. Connection of one conductor of one cable to plural conductors of the other cable can readily arise.
Such confusion is inherently eliminated by use of a unique length connector for each connection to be made. However, this practice requires as many as five unique length connectors to be available, i.e., for a three-phase tap with neutral and ground carried through, and requires proper installer selection of unique length connectors. Apart from these matters, this type of connecting practice has disadvantage in that all connectors, except for the shortest length one, span plural conductors of one of the cables, thereby providing the potential for interphase short circuit.
In the undercarpet wiring system adopted by the assignee of the subject application, described and set forth in copending commonly-assigned applications Ser. Nos. 42,369 and 42,544, respectively entitled "Multi-conductor Cable Arrangement and Electrical Connection" and "Multiconductor Cable", cables to be interconnected are placed in mutually overlapping relation, as contrasted with the above-noted mutually abutting relation. In such overlapping arrangement, a matrix of possible connection zones is presented. For example, in a three-conductor to three-conductor tap, nine zones are in the overlap area, each zone presenting a unique pair of conductors for possible connection. Those conductor pairs to be connected are perforated and an insulation displacing/piercing connector is inserted through the perforation and is crimped onto those cable surfaces exterior to the overlap. A common-sized connector is used throughout and has no expanse, when crimped, which extends outwardly of the connection zone involved. There is thus no need for diverse-sized connectors at installation and no need for care in connector selection by an installer. Since the connectors do not span plural conductors of one cable, short-circuiting possibility, arising from an individual connector, is diminished. These advantages are seemingly set off, however, by a loss of the advantage inherent in the use of different-sized connectors and noted above, i.e., a lessening of the possibility of the connection of one conductor of one cable to plural conductors of the other cable.